what is with this pillager banner?

Slimes do the same thing

That's a thing that happens in bedrock. Banners render in front of water, it's weird.

oh ok. thanks

Yeah. Bedrock is weird that way.

Did you know you can make a space cannon using command blocks?

Command block type: repeating

Command: summon end_crystal ~ ~1 ~ (it's either end_crystal or ender_crystal, not sure)
Lever next to the CMD block, pull it, wait 20ish secs then turn off lever. Hold totem in your offhand, get elytra, have second totem in hotbar and some fireworks, then stand in the crystals, shoot down with a bow, and congratulations you're now in the stratosphere. Have fun flying millions of blocks in any direction.